Add copy constructor and assignment operator to the BitVector class.

src/data-flow.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 18 matching lines @@
 #define V8_DATAFLOW_H_
 
 #include "v8.h"
 
 #include "ast.h"
 #include "compiler.h"
 
 namespace v8 {
 namespace internal {
 
-class BitVector {
+class BitVector BASE_EMBEDDED {
  public:
-  explicit BitVector(int length) : length_(length) {
+  explicit BitVector(int length)
+      : length_(length), bits_(Vector<uint32_t>::New(1 + length / 32)) {
     ASSERT(length > 0);
-    bits_ = Vector<uint32_t>::New(1 + length / 32);
     for (int i = 0; i < bits_.length(); i++) {
       bits_[i] = 0;
     }
   }
 
+  BitVector(const BitVector& other)
+      : length_(other.length()),
+        bits_(Vector<uint32_t>::New(1 + other.length() / 32)) {
+    CopyFrom(other);
+  }
+
   ~BitVector() { bits_.Dispose(); }
 
+  BitVector& operator=(const BitVector& rhs) {
+    if (this != &rhs) CopyFrom(rhs);
+    return *this;
+  }
+
   void CopyFrom(const BitVector& other) {
     ASSERT(other.length() == length());
     for (int i = 0; i < bits_.length(); i++) {
       bits_[i] = other.bits_[i];
     }
   }
 
   bool Contains(int i) {
     ASSERT(i >= 0 && i < length());
     uint32_t block = bits_[i / 32];
@@ skipping 17 matching lines @@
     }
   }
 
   void Intersect(const BitVector& other) {
     ASSERT(other.length() == length());
     for (int i = 0; i < bits_.length(); i++) {
       bits_[i] &= other.bits_[i];
     }
   }
 
+  void Clear() {
+    for (int i = 0; i < bits_.length(); i++) {
+      bits_[i] = 0;
+    }
+  }
+
+  bool IsEmpty() {
+    for (int i = 0; i < bits_.length(); i++) {
+      if (bits_[i] != 0) return false;
+    }
+    return true;
+  }
+
   int length() const { return length_; }
 
  private:
   int length_;
   Vector<uint32_t> bits_;
 
-  DISALLOW_COPY_AND_ASSIGN(BitVector);
 };
 
 
 // Forward declarations of Node types.
 class Node;
 class BranchNode;
 class JoinNode;
 
 // Flow graphs have a single entry and single exit.  The empty flowgraph is
 // represented by both entry and exit being NULL.
@@ skipping 357 matching lines @@
   VarUseMap live_vars_;
 
   DISALLOW_COPY_AND_ASSIGN(LivenessAnalyzer);
 };
 
 
 } }  // namespace v8::internal
 
 
 #endif  // V8_DATAFLOW_H_